Pitfalls in the analysis of ancient human mtDNA

The retrieval of DNA from ancient human specimens is not always successful owing to DNA deterioration and contamination although it is vital to provide new insights into the genetic structure of ancient people and to reconstruct the past history. Normally, only short DNA fragments can be retrieved from the ancient specimens. How to identify the authenticity of DNA obtained and to uncover the information it contained are difficult. We employed the ancient mtDNAs reported from Central Asia (including Xinjiang, China) as an example to discern potentially extraneous DNA contamination based on the updated mtDNA phylogeny derived from mtDNA control region, coding region, as well as complete sequence information. Our results demonstrated that many mtDNAs reported are more or less problematic.Startim, from a reliable mtDNA phylogeney and combining the available modern data into analysis, one can ascertain the authenticity of the ancient DNA, distinguish the potential errors in a data set, and efficiently decipher the meager information it harbored. The reappraisal of the mtDNAs with the age of more than 2000 years from Central Asia gave support to the suggestion of extensively (pre)historical gene admixture in this region.     

Expression of recombinant human lysozyme in the milk of transgenic mice

Human lysozyme is a 130-aa (amino acid) alkaline polypeptide, and has both anti-bacterial and anti-viral properties which make it an important component of human natural immunity system. As a first step toward the ultimate goal of improving the anti-bacterial properties of bovine and ovine milk, a transgenic mouse that contains the genomic DNA sequence of the human lysozme gene has been generated for the first time. From 83 mice generated by microinjection, a total of 6 positive transgenic mice were identified by PCR and Southern blot. F1 mice positive for transgene in lines were also detected by PCR. This shows that transgene could be transmitted from founder transgenic mice to their offspring. Recombinant human lysozyme (rHlys) was found in the whey of 3 female positive transgenic mice by Western blot. The highest concentration of rHlys for transgenic mice was 0.2mg/mL. The antibacterial activity of the whey for transgenic mice was highly enhanced up to 0.4 times as much as that of human, while that of non-transgenic mouse was very low. Although the lysozyme activity of transgenic mice is still lower than that of human, the rHlys exhibits the same specific activity as that of human lysozyme. It provides a strong basis for further studies into the possible application of rHlys express in mammary gland.     

五毒探源——从金庸笔下的“五毒教”谈起

在金庸先生的笔下，“五毒教弦是一大江湖教派，出现在《笑傲江湖》及《碧血剑》中。“五毒教”得名于五种动物：一蛇，二蜈蚣，三蜘蛛，四蝎子，五蟾蜍。中国民间将这五种动物称为“五毒”。在很早以前，我国的中医药先驱就开始应用“五毒”来治疗特定的人类疾病，     

环境化学污染物与人类健康

中国是经济发展最快的发展中国家之一，一方面快速发展的经济使人民生活不断提高，另一方面环境污染、尤其是环境化学物的严重污染对人体健康带来多种危害，包括呼吸系统疾病、神经系统疾病、肿瘤、出生缺陷等，甚至死亡。毋庸置疑，严重的环境污染可导致受害的众多民众失去健康和劳动能力，甚至丧失生命，是重大的社会问题乃至国际化问题，如著名的英国伦敦烟雾事件、美国洛杉矶汽车尾气事件以及日本新泻的水俣病．     

从海底观察地球

随着新世纪的到来,海洋科学界正在着手建设海底观测系统网络,以探测和理解大洋系统的物理、化学、生物和地质等过程,这是继地面/洋面和空间之后观测地球系统的第三个平台——从海底进行连续的实时观测,将使得人类可长期"呆"在海里,从而改变人类和海洋的关系。     

技术伦理如何避开人类中心主义和生物中心主义——约纳斯《责任的命令:寻求技术时代的伦理》解读

存在主义哲学家约纳斯撰写的《责任的命令:寻求技术时代的伦理》是当代环境伦理学的名著,德文版在不到10年的时间里重印了九次,销售了20万册,"责任的命令"成了德国绿党及其同情者的口令。自费希特与黑格尔以来,从未有哪一本哲学著作如此大地影响公众生活。本文基于该著的解读,认为约纳斯的技术伦理克服了现代虚无主义,避免了人类中心主义与生物中心主义的纷争,为环境伦理奠定了一个可靠的形而上学基础。     

我们必须离开地球？（上篇）

世界著名科学家霍金认为,全球变暖、核战争和病毒都有可能在未来某一天彻底毁灭地球上的生物,因此人类探险的范围需要远远超过地球,以保证人类能够长期存活下去。霍金说:“只要人类被困在独一无二的一个行星上,人类的长期生存就处在危险中。小行星撞击地球和核战争等威胁迟早会将我们消灭殆尽。但是,一旦我们向太空扩展并建立自给自足的聚居地,我们的未来应该是安全的。太阳系没有一个类似于地球的地方,因此我们必须寻找另外一颗恒星。”     

术语是折射人类思维进化的一面镜子——《比亚韦斯托克宣言》阅读笔记

文章从科学与语言实际上是并行发展的这一视点出发,以《比亚韦斯托克宣言》的主要观点为依据,试图说明,通过对某一历史时期某些学科的术语发展水平的研究,可以透视出该时期人类思维的进化与发展水平。这实际上属于人类语言学研究的视野,对当前人们关注的认知科学研究也具有很大的启示意义。     

移民外星球有了新希望

寻找新的居住领地一直是人类的梦想。最近，欧洲科学家发现了一个太阳系外可能适合人类居住的星球，那个星球上很可能有水，也可能有生命存在。这个发现为人类移民外星球提供了新的线索。     

综合媒质的设计语言表达

设计是一个将构想转化为现实的创造性过程,设计表现图是设计师运用各种媒介、技巧和手段来说明设计构想、传递设计信息、交流设计方案并籍此征询评审意见的工作,是整个设计活动中将构想转化为可视形象的重要环节.当今文化的格局呈现出更开放、更多元、更包容的态势,可以说"多元"与"综合"已成为当代人类文化环境的一个显著特征.